Thanks all,
As mentioned it started showing E3 most of the time earlier this week, it then showed E6 a couple of times and got a lot worse, So I decided to have a closer look and I think the sensor collar might have moved a little.
As it was a little noisy I decide to change the head stock bearing first, so ordered on Thursday and fitted yesterday, is was fairly easy, less than an hour to complete the task. I have only ran it up a few times to see, it now runs a great deal more smoothly and did not show any errors. I hope to do a little turning tomorrow so we will see if its cured the problem, I am also going to check the motor brushes and probably fit new, after that if I still have a problem with error codes I will let you know and see what else can be done.
Thanks very much for your feedback, most helpful and it also pushed me to try and sort it out myself.
Neil